1. Field of the Invention
The invention relates to the technological field of steam turbines. It relates to a method of manufacturing a plurality of steam turbines for use in various applications which differ in the respective thermodynamic parameters such as, for example, cooling-water temperature, ambient temperature, given boiler data, process-steam requirement, etc., the steam turbines in each case having at least one high-pressure stage with first blading and a control-wheel stage for part-load operation.
2. Background of the Invention
In the manufacture of steam turbines, which may exist as individual high-pressure (HP) machines or as combined high-pressure/intermediate-pressure (HPIP) machines, the blading of the high-pressure and/or intermediate-pressure part, in the event of an order being placed, is designed individually to the data required or specified for the respective application. This also includes--if there is a control-wheel stage for part-load operation--the individual design of the control-wheel stage with respectively adapted duct height (of the wheel duct) and an adapted number of wheel blades or nozzles arranged in an annular shape upstream of the control wheel in the direction of flow (for details of such control-wheel stages, reference may be made, for example, to publications U.S. Pat. No. 4,812,107, U.S. Pat. No. 4,881,872 and U.S. Pat. No. 4,979,873).
The result of this individual adaptation of the steam turbine is that, with each order, new customer-specific production documents have to be prepared for the entire blading including the small accessories and the control-wheel stage. A repetition effect during the production, of the control wheel too, is thus largely ruled out. This procedure certainly has the advantage that any customer-specific variation within the blading can be realized with the existing design tools. A disadvantage, however, is that possible cost-saving potentials are very small and are restricted to fine design details permitted by the existing design tools.